Re: [PATCHv2 29/29] Documentation/x86: Document TDX kernel architecture

From: Xiaoyao Li
Date: Thu Feb 24 2022 - 04:09:07 EST


On 1/24/2022 11:02 PM, Kirill A. Shutemov wrote:

+#VE due to CPUID instruction
+----------------------------
+
+In TDX guests, most of CPUID leaf/sub-leaf combinations are virtualized by
+the TDX module while some trigger #VE. Combinations of CPUID leaf/sub-leaf
+which triggers #VE are configured by the VMM during the TD initialization
+time (using TDH.MNG.INIT).
+

The description is incorrect.

TDH.MNG.INIT does not configure whether the CPUID leaf/sub-leaf triggers #VE or not. It configures if some feature bits in specific leaf-subleaf are exposed to TD guest or not.

Whether the CPUID(leaf, sub-leaf) causes #VE or not, is defined in TDX spec, and not configurable by user or VMM.